Laser processing, such as micromachining, can be conducted on numerous different work pieces using various lasers effecting a variety of processes. For example, lasers are used to drill vias in and ablate material from electronic materials products, such as homogenous films, particulate filled resins, polyimides, and fiber reinforced polymers, either with or without metal cladding.
A goal of laser micromachining operations is to provide consistent quality of laser micromachined features from work piece to work piece and over an entire work piece. In general, the quality of a laser-processed material refers to a standard of excellence specified by a customer of laser processing equipment. Quality metrics differ for different laser processing operations. Some measures which define feature quality include the location, size, and shape of the feature. Other measures include sidewall angle, bottom texture, the amount of cracking near the edge of the feature, as well as the volume and texture of debris left in the feature after micromachining.
One problem with laser micromachining operations as discussed herein is that, due to non-uniformities in the work pieces, performing the machining operations with the same laser parameters on two different work pieces or at two different locations on the work piece can result in differences in feature qualities. Examples of work piece differences that influence the results include differences in thickness, differences in work piece flatness, and differences in surface preparation that makes the work piece more or less reflective of laser power. These variations are not constant from work piece to work piece or over an entire work piece and can vary depending upon location down to an individual feature. However, in some cases, these variations can be repetitive from work piece to work piece in a given lot of work pieces due to normal variations in manufacturing tolerances.
To address part of this problem, the thickness of a work piece is measured and a operator manually determines what laser processing recipe should be used. The user then conveys the recipe to the laser processing system.